1. Field of the Invention
The present invention relates to a bearing assembly, and more particularly to a bearing assembly with multiple rows of balls mounted therein to bear a heavier load.
2. Description of Related Art
Referring to FIG. 8, a ball bearing in accordance with the prior art comprises a bearing cover (40), a positioning collar (44), multiple balls (46) and a bearing race (42). The positioning collar (44) is co-axially mounted on the bearing cover (40). A row of balls (46) is located between the bearing cover (40) and the positioning collar (44) in a bearing race (42), such that the race (46) can rotate relative to the bearing cover (40) and the positioning collar (44) with very little friction. However, because the ability to bear a load depends on the number of rows of balls (46), the conventional bearing with a single row of balls (46) is not able to bear a large load between the rotating and stationary members. In addition, the conventional bearing is difficult to manufacture and assemble because the structure of the bearing cover (40) is complex.
Referring to FIG. 9, a bearing with two rows of balls (54) in accordance with the prior art comprises a tubular member (50) and a sleeve (52) mounted on the outer periphery of the tubular member (50). A row of balls (54) is received between the tubular member (50) and the sleeve (52) on each end of the sleeve (52), and a holder (56) is mounted to abut each row of balls (54) to maintain their position. The sleeve (52) can rotate relative to the tubular member (50) with little friction, and a bearing with two rows of balls (54) is achieved.
However, although the conventional bearing with two rows of balls (54) can bear a heavier load better than that of the conventional bearing with a single row of balls, the conventional bearing with two rows of balls (54) still lacks the ability to bear a very large load. In addition, there is no supporting effect between the rows of balls (54) when they are a long distance apart.
To overcome the shortcomings, the present invention tends to provide an improved bearing assembly to mitigate or obviate the aforementioned problems.